This invention relates to a lubricator, and in particular to a side access lubricator.
In many downhole operations, such as carried out by those working in the oil and gas exploration and extraction industry, tools, valves, packers, sensors and other devices are run into and retrieved from well bores using flexible relatively small diameter supports, such as coil tubing, slickline or wireline. The support passes through a lubricator stuffing box and grease head comprising a tubular body which is mounted above an opening providing access into the well bore. The lubricator may be supported in a derrick or from a crane jib.
The lubricator provides a lock via which tools may be inserted into and retrieved from a well which is under pressure. To insert a tool, the well is closed below the lubricator and pressure within the lubricator is bled off. The lubricator may then be opened to receive the tool, which is coupled to the end of the support. The lubricator is then closed and the well opened below the lubricator, allowing the tool to be run into the well. Conventionally, the lubricator must be removed from its normal position above the well bore opening to permit opening and insertion of a tool, requiring derrick or crane intervention.
It is known to provide side access lubricators with hinged doors which may be opened to allow insertion and retrieval of tools without removal of the lubricator and thus without derrick or crane intervention.
It is among the objectives of embodiments of the present invention to provide an improved side access lubricator.
According to the present invention there is provided a lubricator comprising a tubular body defining a side access port, a tubular sleeve mounted on the body and movable between a first position in which a wall portion of the sleeve closes the body port, and a second position in which the body port is open, permitting access to the body interior.
The invention also relates to a method of locating or retrieving tools from such lubricators.
The use of a sleeve to close the body port facilitates sealing of the port.
Preferably, the body and sleeve are cylindrical.
Preferably also, the sleeve is movable between the first and second positions by one or both of rotation and axial movement relative to the body. Most preferably, the sleeve is axially movable relative to the body such that a seal between the body and the sleeve may be provided merely by the provision of, for example, two sets of annular seals either on the body above and below the body port, or adjacent the ends of the sleeve.
The sleeve may be moved between the first and second positions by any convenient means, and preferably by means of a piston and cylinder arrangement, and most preferably a pair of pistons and cylinders, one mounted to each side of the body and sleeve. of course other means may be utilised, for example a manual arrangement, or motor driven arrangements.